Arbitrage Opportunity at Under Armour?

I read an interesting article on the Wall Street Journal recently. The article described an apparent arbitrage opportunity at the sportswear company Under Armour. The corporation issued a new class of C stocks to shareholders in March. The difference between this new stock is voting rights: while Class A shares have one vote and Class B shares have 10 votes, Class C stocks have none.

However, Under Armour CEO Kevin Plank has 65.3% of the vote (holds all B shares), according to the WSJ. Thus the vote held by Class A shares has no practical value. Consequently, one would expect that Class A and Class C shares be valued similarly. In fact, this is what we see between voting and non-voting shares at companies such as Alphabet and Viacom.

Yet, as of Nov. 25, the Class C shares were trading at a 22% discount to their Class A counterpart. Here is a link to the article.

Why are the C shares sold at such a large discount? And doesn't this present an opportunity for investors to short Class A shares while going long on C shares? Thoughts monkeys?